Method of making titanium and zirconium alloys



atent' lVlETHOD OF MAKINGTITANTUTVTANTT T fional Distillers and ChemicalCorporation, New York,

N.Y., a corporation of Virginia No Drawing. Filed Oct. 2, 1958, Ser. No.764,764 7 Claims. (Cl. 75-135) This invention relates to a new anduseful process in the production of zirconium 'or titanium metal alloysand/or alloy powders in a substantially continuous man,- ner. Moreparticularly, it relates to a combination process comprising lowtemperature reduction of zirconium or titanium tetrachloride in thepresence of other metal halides and/or other metals with alkali metalsand a heat treatment of the finely divided reaction product from the lowtemperature reduction to convert the metal to metallic zirconium ortitanium alloy sponge or to nonreactive alloy powder.

This application is a continuation-in-part of Serial No. 569,968, filedMarch 7, 1956, now abandoned.

Although, for many applications in the powder metallurgy field, thehardness of alloys such as those of'tita-L nium is not critical, otherfactors present difficulties. At present, two types of methods are usedfor obtaining powdered titanium metal for use in powder metallurgy. Onetype employs a process in which the massive titanium metal is comminutedby grinding or crushing and the other treats titanium spongewith'hydrogen' to produce the hydride which is then decomposed to formmolding powder. In either case, the powder thus obtained must then bemechanically mixed with the elements required to form the titaniumalloys.

Alloys of titanium which contain small percentages of other metals areprepared by mechanically mixing titanium sponge with the alloyingelement'and then compressing the mixture into a consumable electrode forare: melting to an ingot. Double melting of the ingot is essen-' tial toobtain a completely homogeneous metal alloy. This extra arc melting stepwould not be required if the sponge and alloying metals could beobtained in analform and homogeneous mixture at the start.

For many applications, alloy powders are more important than purezirconium or titanium sponge or powder. For instance, as describedabove, difliculties are encountered in preparing and maintaining uniformpow dered metal mixtures prior to pressing and sinteringthe parts formedin powder metallurgy. Another great advantage of powder metallurgy overthe conventional methods, especially for expensive metals is thatapproximately 100% of the zirconium or titanium and the alloyingelements end up in the finished article rather than the usual 50%. Inthis manner, for example, powdered titanium metallurgy is a good answerto the vital titanium scrap problem. Thus, with a suitable titaniumalloy molding powder prepared as herein described it is feasible toproduce, for instance, compressor blades using the new hot coiningtechnique. In this process, a part is pressed and sintered to slightlyover-size, then while still hot, at a temperature of around 900 C. thearticle is forged in a coining process which completely closes the poresand yields a very accurate massive titanium article.

In the Kroll process for metallic titanium, titanium tetrachloride isfed into the reactor which contains molten magnesium metal. Operatingunder such conditions, it is 3,904,848 Paitented Oct. 17,

"ice

impossible to reduce a mixture of titanium tetrachloride and other metalhalides and thereby obtain a uniform metal spongecomposition.Another'ieason for segregation of metals during the reduction is thewicking action of the titanium sponge on the molten magnesium. This isparticularly significant since this process normally utilizes forreduction 85% or less of the magnesium placed in the reactor. Theremaining amount (about is present at the end of the reduction as freemagnesium and remains dissolved in the titanium sponge in a. non-uniformmanner.

Substitution of sodium for magnesium under similar E conditions does notsolve this difficulty of non-uniformity.

Likewise, electrolytic processes do not serve satisfactorily forproduction of zirconium and titanium alloys. The position of thealloying elements in the electromotive series, or more specifically thesingle electrode potential of the metallic ions, indicate that eitherzirconium or titanium would electroplate to the practical exclusion ofthe alloying elements or, vice versa, depending on the alloying metalsinvolved.

It is the object of this invention to describe a process whereby a metalsponge and/or non-reactive metal powneous alloy ingots and parts.

ders may be produced containing the zirconium or the titanium and thealloying metals in substantially molecular mixture, thus eliminating thecostly and time consuming techniques now required for producing homoge-Even more particularly, it has as an additional objective the productionof a sponge directly usable'in powder metallurgy without the difiicultcomminuting processes presently required to obtain the desiredmetalparticle size for use in powder metallurgy. Sponge or alloy powderis produced in proper screen analysis.

Thus, the invention comprises essentially a low temperaturesodiumreduction process and a heat treating operation wherein requiredalloying elements are incorporated directly into final sponge or powderby using mixtures of the halides of the alloying metals or of thealloying metals with the zirconium or titanium chlorides.

Alloying metals such as aluminum and/or vanadium, chromium, tin,molybdenum, iron or manganese are incorporated uniformly into the spongeby using zirconium on reduction, a uniform mixture of finely dividedmetal tetrachloride or titanium tetrachloride containing necessaryamounts of the halide or the halide mixture of the particular desiredalloying metal or of theparticular desired alloying metal itself. Thus,there is obtained,

powders which on sintering would produce a sponge or non-reactive powderof uniform composition with respect to the zirconium or titaniumcomponents and particularly with respect to the alloying metal content.

This process is especially'well adapted and designed to produce suchalloys and alloy powders. Operating as herein described, mixtures ofcompounds of two or more metals are reduced concurrently orsimultaneously to.

produce especially prepared and finely divided alloy powders. nium andiron; titanium and manganese; titanium and tin;

titanium, chromium and iron; titanium and aluminum and the like canreadily be obtained. Many other mixtures of metal powders can be thusobtained as desired. In general, commercial titanium alloys containrelative minor proportions, that is, no more than 10% total of the otheralloying elements. Among the more common.

alloying elements for titanium are aluminum, manganese, vanadium,chromium and tin. For zirconium the most Alloy powders of titanium andcopper; titaQ usual alloying metal is tin (2-3%). Typical examples ofthe more numerous titanium alloys are the following:

Titanium with 8% manganese.

Titanium with 4% aluminum and 4% manganese.

Titanium with 6% aluminum and 4% vanadium.

Titanium with aluminum and 1% iron and 1% chromium.

Titanium with 5% aluminum and 1% each of iron,

chromium and molybdenum.

Titanium with 3% manganese and 1% each of molybdenum, vanadium, chromiumand iron.

Titanium with 5% aluminum and 2 /2 tin.

Titanium with 3% aluminum and 5% chromium.

The use of an alkali metal, and in particular sodium, permits operationof a process in which there is a separation, or at least a partialseparation of the chemical reduction step from the sponge forming stepwhereby the chemical reduction step is at least in part carried out atany temperature above the melting point of the alkali metal and belowthe melting point of the alkali metal halide by-product. WhenSOCllllIl'l is used, the by-product salt is sodium chloride. It has alsobeen found that at relatively low temperatures the product of thereaction is a free flowing finely divided mixture of reduction productsand by-product alkali metal halide produced according to the followingequations resulting in mixtures of titanium sub-halides (withsubstantially no titanium being present in the event less thanstoichiometric amounts of sodium are used that is 25% to 50% of theamount required for theoretical reduction to the metal):

(a) 2Na+TiCl TiCl +2NaCl (b) Na+TiCl TiCl +NaC1 in actual operation anincomplete reduction according to Equations a and 1) yields a solidpartially reduced intermediate reduction product. As the finely divided,solid product fills the reactor, having started with a partial charge offinely divided salt as a heel," further product is withdrawn, preferablycontinuously, by means of, for example, a screw conveyor leading awayfrom the reaction vessel from a location on the side of the vessel nearthe top flange. 1

Another embodiment of the invention involved reacting less than thestoichiometric arnount of sodium with the zirconium or titaniumtetrahalides and the alloying metal halides so that a solid, finelydivided mixture consisting substantially of the lower valence halides ofzirconium or titanium and the alloying metals is formed. This reductionis carried out at any temperature above the melting point of sodium butbelow the melting point of the reaction mixture. The remaining sodiumrequired for stoichiometric reduction is then added and allowed to reactwith suiiicient heat being liberated to melt the by-product salt andcause the finely divided metals produced to form an inert spongy mass ofthe metals in intimate, uniform mixture.

A typical reduction system for the partially reduced mixtures isdescribed below. The reduction reactor consists of a cylindrical vesselin which a rectangular or anchor type stirrer operates, which stirrer iscapable of mamtaining the solid reaction medium of finely divided powderand by-product salt in an agitated state. Appropriate amounts of sodiumand zirconium tetrachloride or titanium tetrachloride with the desiredhalides of the alloying metals or the metals themselves are fed intothis reactor at such controlled rates that the temperature therein is inthe range of from above the melting point of sodium to the melting pointof the mixture, but preferably in the 150-450 C. range. The capacity ofthe reactor to produce product will, of course, vary with the surfacearea and size of the vessel walls and/ or other means provided todissipate the heat of the reduction reaction of the metal halides withthe alkali metal. As the solid substantially dry reaction product fillsthe reaction vessel, it is withdrawn either continuously ordiscontinuously by means of, for instance, a screw conveyor systemattached to the side of the reaction vessel. The dry product is allowedto fall or is passed into a sintering vessel for completion of reductionand heat treatment of the resulting alloy powder at temperatures abovethe melting point of the reaction mixture or of the alkali metallay-products. The entire reduction and heat treatment operations arepreferably carried out in aninert atmosphere, for instance, under ablanket of an inert gas such as argon or helium.

The required amount of sodium necessary for completion of reduction isadded and the finely divided mixtures of metals and, by-product salt isthen brought to a term perature above the melting point of sodiumchloride and held for a controlled period of time by, for example,immersing the sintering pot in a furnace maintained at the appropriatetemperature. The metal alloy-salt mixture is preferably maintained at atemperature of about 850- lO50 C. for a period of from 1 up to about 5to 20 hours. At the completion of the heat treatment, the sinteringvessel and contents are removed from the furnace and allowed to cool toroom temperature after which the alloy sponge is removed and recovered,Molten salt may be drained from the metal alloy sponge if desired, priorto cooling. The product from this process can be freed from by-productsalt by washing with water with production of a metallurgical gradealloy sponge.

Several variations which are quite satisfactory for operating thisinvention are described below although this list is not to be consideredas limiting the invention in any way. For instance, zirconium ortitanium tetrachloride together with side streams of halides of theselected alloying metals are simultaneously and continuously orsemicontinuously fed into the low temperature reduction vessel withamounts of sodium to partially reduce the zirconium or titaniumtetrachloride and other metal halides to a free flowing powderconsisting substantially of subhalides and by-product salts which may ormay not contain any free metals. The only requisite here is that thepowder to free flowing, easily transferable, and essentiallynon-volatile at the temperatures of handling.

If this operation is used, the predetermined amount of sodium tocomplete the reduction may be first introduced into the bottom of thesinter vessel and the partially reduced powder mixture placed on top ofthe solidified sodium. At any rate, the reaction in which completion ofthe reduction occurs should proceed as rapidly as possible in order toavoid crystal formation and yield a homogeneous sponge. Upon reachingabout C. after placing in the sintering furnace the reduction reactionrapidly completes itself with the release of enough heat to bring thewhole reaction mass to 800950 C. in 15 to 60 minutes depending on thelevel of reduction permitted in the first stage.

This mode of separation of the reduction reaction into two stages is ofdistinct advantage in the production of titanium or zirconium alloysponge since alloying elements are thoroughly mixed in at an essentiallynon-volatile state and are reduced to metal in situ by sodium as itvaporizes upward and throughout the mass. The speed with which this lastpart of the reaction takes place is also a great factor in preventingsegregation. Very little time for crystal growth is allowed so a uniformmetal alloy sponge free of crystals results.

A second method of operation which is especially adaptable Where thealloying halide is not soluble, involves the reduction of TiCl or ZrCL;to the dichloride or other intermediate subhalide stage, but at whichstage the parti-' ally reduced sub-halides are finely divided and freehowing powders. This mixture is then blended with the powdered alloyinghalide either as a separate operation or in the heat treating vesselitself which contains the requisite amount of sodium to complete thereduction in the heating furnace. After the alloying metal halides havebeen added and admixed therewith, the sintering process is the same asin the process described above.

While some inorganic halides, of the desired alloying metals are solublein and miscible with titanium and zirconium tetrachlorides others areessentially insoluble. Therefore, it is frequently advantageous to use acombination of the above described procedures. That is, the solublemetallic halidesare added with the titanium tetrachloride and theinsoluble alloying solid halides are added as a powder to the chargejust before sintering.

Still another mode of operation is carried out by combining a part orall of the alloying metals in the form of finely divided metal powderseither simultaneously with the sodium reduction in the first or lowtemperature stage, or preferably by combining, with good mixing, thefree metal powders into the partially reduced mixture in the sinteringvessel just prior to the sintering operation. In this case, only thatamount of sodium is placed in the sintering pot which is needed tocomplete the reduction of the zirconium or titanium component of thealloy in the high temperature or sintering stage. In actual practice,the alloying metals or the halides of the alloying metals can becombined with the low temperature reduction product at any point afterthe reduction step and prior to the actual final sintering operation.

' By operating at a sodium deficiency in the reduction step it is meantthat there is added thereto only enough sodium to form the subhalidessuch as subchlorides of the halides of higher valency, for instance:

More broadly, the reaction may be interrupted at the first or lowtemperature stage at, for instance, 25% reduction, 50% reduction, 75%reduction, 90% reduction, and the like. The only important requirementat this stage of the process is that the reaction product must be aneasily mechanically transportable powder which is insensitive totemperature, i.e., it is not likely to form melts which solidify toconcrete-like materials should the reaction temper- 5 out the electrode.

1 arate additions of columbiurn, tantalum and aluminum being requiredbefore a homogeneous ingot could be ob tained. One advantage of thesedirectly produced alloy sponges is thatthese difiiculties are avoidedand a double or, in

5 some cases, multiple arc melting at the ingot stage is unnecessarysince this is only practical on a relatively small,- experimental scale.As pointed out above, it has been found that when the alloying elementsare fed into the melting crucible, as a side stream,'e.g., along withzirconium or titanium sponge, or mixed with the conium or titaniumsponge and compressed to form a consumable electrode, at least a secondmelting is required to insure homogeneity in the ingot. With the alloysponges and alloy powders provided according to this invention, thesemeltingttechniques are unnecessary.

The degree of non-melting segregation in;an ingot is afiected'by theparticle size of the alloy or mixture. As the particle size decreases,the extent of segregation de creases. Ingots made with a mixture of themetal powders show less segregation than ingots made from mixtures ofthe metals scrap. V v

' It is not known, generally, or in any particular case, of alloycomposition just what degree of fineness of particle size of these metalpowder mixtures can be used and-will not result in segregation and willthus provide a homogeneous ingot using a conventional two-stage meltingtechnique.

Itis generally uneconomical to use relatively high cost metal powders,singly or in mixtures and to provide these 40 in particle sizes smallenough to permit production of homogeneous-alloy ingots usingconventional melting ature, momentarily and in isolatedzones become adue to a momentary unbalance of raw material feeds.

After the sponge growth phase of the process is completed, and thisusually requires from 1 up to 5 to 20 hrs. at 850-900 C. up to 1100 C.,the sintering or heat treating vessel is removed from the furnace andpreferably, the major part of the by-product salt removed either bytapping or by at least partially inverting the vessel and allowing themolten salt by-product to drain away from the sponge which may or maynot adhere lightly to the bottom and/or sides of the sintering vessel.The whole mass is then allowed to cool to room temperature. Thereafter,the vessel is opened and the sponge containing some residual salt isremoved. The sponge with the contained salt is then crushed to suitablesize, leached with water I of the constituent halides can be preparedand fed s1- which may contain a small amount of acid, if desired, toneutralize any alkali which may be present from the slight excesses ofthe reducing alkali metal and/or to solubilize and stabilize againstoxidation and hydration any trace amounts of'diand tri-chlorides oftitanium or zirconium and other incompletely reduced metallic halides.The washed alloy sponge is then dried and is ready for use.

Homogeneity in commercial titanium and zirconium alloy ingots has longpresented a serious problem. Arc melting is preferably used, since thismelting technique, when properly used, is the only one which results inuncontaminated alloys. However, alloy ingots produced in this typefurnace are often severely segregated.

For small ingots, homogeneity can be achieved by melting and remeltingon both sides of a pancake in a special furnace. This is also limited,to small ingots because of very limited depth of melting which can beachieved.

. Consumable electrode arc melting can also be done in which electrodesareforrned by pressing and sintering the 7 Using this process, ispossible to obtain and employ the finely divided powders necessary forhomogeneity in the alloys without the expense and difficulties ofproducing them from sponge, and with superior results in making ofhomogeneous alloy ingots.

' Another great advantage is that metal powders of the necessaryalloying free metals do not need to he provided in a puresta'te, onlythe pure chlorides are necessary and these are much more easilyprepared. However, in

" some cases as pointed out above, some of the alloying elements canbest be added as metal powders. In actual operation of the invention,the halides of the alloying metals that are sufficiently soluble will bemutually dissolved and added as a solution so that'a master mixturemultaneously into the low temperature reduction stage, For example,vanadium chloride and stannic chloride are typical of metal halideswhich are soluble in titanium tetrachloride. Since zirconiumtetrachloride is a solid, all alloying elements would be added as sidestreams rather than in solution for zirconium alloy sponge.

Powder metallurgical applications require minus 20 to plus 200 meshmaterial. Thus, another advantage of this process for titanium andzirconium alloy sponge, lies in the fact that in contrast to Krollmagnesium sponge, alloy sponge by this sodium reduction technique can becorhminuted easily because of its lower bulk densityto powders suitablefor powder metallurgy. This is partic ularly important in the case, oftitanium alloys where sponge produced commercially by magnesiumreduction of titanium tetrachloride cannot, except with great difficultybe broken down mechanically to particles suitable for powder metallurgy.For example, one method for converting magnesium produced titaniumsponge to pow der is to convert it to titanium hydride by reacting withhydrogen at elevated temperatures and then to decompose this hydride byfurther heating to obtain a suitable powder. This lengthy and expensiveprocessing is avoided completely by the herein described process.

Operating according to this new process, the alloy sponges whichresultare not mixtures but substantially true alloys. This overcomes adifficult existing problem not only in the homogeneous and completemixing of alloying powders but also in keeping them mixed duringhandling operations prior to pressing into the green mold.

It is to be understood that this process operates to produce a widevariety of metal alloys. Actually the mixture of metal halides fed tothe reduction step or the alloying metal added can be varied over almostany range to produce the desired alloy composition in controlled andexact proportions. Such an alloy sponge results in a great saving intime to the fabricator from several standpoints. It is not necessary tohandle and feed several metal powders of varying purities, all requiringrepeated analyses. The metal alloy product is purer and more free ofinterstitial elements, since metal powders always tend to becomeoxidized and thus carry oxide film layers into the final ingot.

The true alloy sponges permit the powder metallurgical formation by hotcoining techniques of many parts such as compressor blades whichotherwise must be machined from titanium alloy billets with the usual50% and greater losses. Powder. metallurgy operations with such alloysponges give a coined part with almost no waste in fabrication. Thismeans a tremendous saving in cost of the finished parts.

Example 1 Sodium is fed at a uniform rate into a low temperaturereduction vessel for carrying out the first step of the process. Aconstant heel consisting of a mixture of solid, finely divided reductionproducts is maintained by continuously or at least intermittentlywithdrawing product from the vessel as fast as additional product isformed. Simultaneously and at least intermittently titaniumtetrachloride is metered into the reduction zone there being added 8%less sodium than the amount of sodium required, for stoiohiometricreduction. After a period of 17.7 hours, a quantity of 62.6 parts ofTiCl and 34.8 parts of sodium have been added to the reactor vessel. Theresulting product is withdrawn as a salt titanium mixture and is placedin a sintering vessel containing 4.5 parts free sodium. At this pointthe charged sintering vessel is disconnected from the reduction vesseland connected to a weighed hopper containing 6.55 parts of resublimedand finely divided aluminum chloride. The aluminum chloride is addedinto the sintering vessel under an argon atmosphere and the hopperdisconnected. The sintering vessel of size of about 18" diameter by 36"high is then turned end-overend in a turning device to insure thoroughlyintermixing of the aluminum chloride with the products of partialreduction of the titanium tetrachloride and the excess sodium. Aftersuch mixing, the entire mixture in the sintering vessel is placed in thesintering furnace and heated to 850 to 900 C. for a period of 6 hours.The sintered product is then removed from the furnace and the vesselturned on its side to drain the product salt away from the sponge (whichadheres lightly to the bottom) formed during the sinter operation.vAfter cooling, the sponge is removed, ground to 10 meshsize, washedfree of salt with slightly acidulated water, and washed with water on acentrifuge. The excess water is spun from the sponge which is dried in avacuum drying oven. A. quantity of alioy sponge amounting to 14.0 parts,81% yield, is recovered which has a hardness of 190 Brinell and analuminum content of 7.8%.

Example 2 Operating in a manner analogous to that of Example 1, sodium(64.5 parts) is added to the reduction kettle over a period of 16.9hours. During this period, at a uniform rate, 120.5 parts of titaniumtetrachloride is also introduced which leaves 5.67 parts of sodiumunreacted. The hopper is charged with 3.06 parts of anhydrous manganesechloride (equivalent to 1.1 parts sodium) and 6.60 parts of aluminumchloride (equivalent to 4.55 parts sodium). Both metal salts arepreviously finely ground in a ball mill under an argon atmosphere. Thissalt mixture is introduced into the sintering vessel and mixedthoroughly. This sintering vessel is placed into the sintering furnacefor the reduction of the newly added chlorides. The reaction mixture isheated for a period of 10 hours at a temperature of 925 C. The alloysponge, isolated as in Example 1, amounts to 30.1 parts which is a'90.1% yield. The alloy sponge contains 4.0% each of manganese andaluminum with the diiierence being titanium.

Example 3 Quantities of sodium (64.0parts) and a mixture of titaniumtetrachloride and vanadium tetrachloride, 118 parts and 5.0 partsrespectively, are added to thelow temperature reduction kettlesimultaneously and continuously at uniform rates. The halide mixture ispreheated and volatilized into the reaction zone as a gas videdreduction product.

wherein the reduction to the metal takes place at a temperature of 200to 250 C. A period of 16.7 hours is required for the addition of thesequantities of materials and the continuous withdrawal of the solid,finely di- The amount of sodium added is in excess (5.1 parts) over thatneeded to reduce the 118 parts of TiCl, and the 5.03 parts of VCl Thisexcess sodium is equivalent to 9.8 palts of AlCl This amount of aluminumchloride, finely ground, is now introduced under argon into thesintering vessel and thoroughly mixed by turning the sinter vesselend-over-end as described in Example 1 above. The sintering vessel isnow heated under an argon blanket to a temperature of 900 C. for aperiod of 15 hrs. The vessel is then removed from the furnace and placedon its side, to permit draining away of most of the by-product saltbefore cooling. After cooling, the alloy sponge is removed, ground,leached free of salt, dried and analyzed. Alloy sponge amounting to 28parts equivalent to an 84.5% yield, is recovered containingapproximately 6% aluminum and 4% vanadium.

Example 4 Operating as described in Example 1, 120.5 parts of TiCl and61.1 parts of sodium are fed simultaneously into the reduction vesselover an 18.5 hour period at .a reduction temperature of 250 C. Thefinely divided product is continuously withdrawn as formed but there ismaintained aheel of 15 to 20 parts of the solid reaction mixture in thereduction vessel. At the conclusion of this step in the process thesintering vessel, into which the reduction mixture has been transferred,is disconnected from the reduction vessel and connected to theargon-filled hopper which contains 1.0 parts of finely divided aluminumpowder (-300 mesh) and 5.08 parts of powdered CrCl This mixture isintroduced into the sintering vessel. Then the contents of the sinteringvessel are thoroughly mixed by turning end-over-end in a turning device.After this, the vessel is heated in the furnace to 900 C. for a periodof 10 hrs. to effect sponge growth and alloying of the powderedaluminum. The sponge is isolated as in the above examples, by leachingwith water, slightly acidified at first with hydrochloric acid toprevent attack by oxygen of the air on trace quantities of titaniumsubhalides present in the sponge. The resulting alloy sponge of titaniumwith chromium and aluminum amounts to 29 parts which is an 89% yield.This alloy contains approximately 3.1% aluminum and 3.5% chromium.

While there are above disclosed but a limited number of embodiments ofthe invention herein presented, it is possible to produce still otherembodiments without departing from the inventive concept hereindisclosed, and it is desired therefore that only such limitations beimposed on the appended claims as are stated therein.

What is claimed is:

1. A process for the production of an alloy of a metal selected from thegroup consisting of titanium and zirconium which comprises the followingseparate steps: (A) reducing a tetrahalide of a metal from the groupconsisting of titanium and zirconium with an amount of sodium at leastsufiicient to reduce said tetrahalide to a corresponding metal halide oflower valence, but insutficient for stoichiometric reduction to themetal, thereby controlling the reaction temperature within a range fromV the melting point of the sodium up to the melting point of thereaction mixture, said reaction mixture comprising halides of lowervalence selected from the group consisting of titanium and zirconiumsubhalides and the corresponding sodium halide, and forming an easilystirred, solid, finely divided reaction mixture which is stirred duringthe reduction reaction; (B) introducing an alloying material selectedfrom the group consisting of a halide of an alloying metal and analloying metal into said process in any step up to the initiation of thesubsequent slntering period; (C) recovering said solid, finely dividedmixture and subjecting'it to reaction with the required amount ofadditional sodium for stoichiometric reduction of all halides present insaid mixture to form metal alloy of said alloying reactant and saidmetal selected from the group consisting of titanium and zirconium andutilizing the resulting heat of the reduction reaction in heating themixture containing said alloy to a sintering temperature above themelting point of the sodium halide by-product produced, so as to lowerthe time required to attain a sintering temperature for said alloy; (D)maintaining said sintering temperature for a sufiicient period of timeto complete sintering of said metal alloy and to produce a massive metalalloy of said alloying metal and said metal selected from the groupconsisting of titanium and zirconium; and (E) isolating the metal alloyfrom the resulting reaction mixture.

2. The process of claim 1 wherein the amount of sodium employed in step(A) is from about 25 to 90% by weight of the stoichiometric amountrequired for re-' duction of said halide to the appropriate alloy.

3. The process of claim 1 wherein the alloying material is a metal whichis introduced into said solid, finely divided mixture of halides of lowvalence and the corresponding sodium halide just prior to subjectingsaid solid, finely divided mixture to reaction with the requiredadditional sodium in step (C).

4. The process of claim 1, wherein the alloying material is a halide ofany alloying metal which is introduced into said solid, finely dividedmixture of halides of lower valence and the corresponding sodium halidejust prior to subjecting said solid, finely divided mixture to reactionwith the required additional sodium in step (C).

10 5. A process for the production of an alloy of a metal selected fi'omthe groupconsisting of titanium and zirconium which comprises thefollowing separate steps: (A) reducing a tetrachloride of a metal fromthe group 1 consisting of titanium and zirconium with an amount ofsodium at least suflicient to reduce said tetrachloride to acorresponding metal chloride of lower valence, but insufficient forstoichiometric reduction to the metal, thereby controlling the reactiontemperature within a range of about ISO-450 C., said reaction mixturecomprising chlorides of lower valence selected from the group consistingof titanium and zirconium subchlorides and sodium chloride, and formingan easily stirred, solid, finely divided reaction mixture which isstirred during the reduction reaction; (B) introducing an alloyingmaterial selected from the group consisting of a chloride of an alloyingmetal and an alloying metal into said process in any step up to theinitiation of the subsequent sintering period; (CTrecoWe ringsaid solid;*fineiy divided mixture and subjecting it to reaction with the requiredamount of additional sodium for stoichiometric reduction of allchlorides present in said mixture to form a metal alloy of said alloyingreactant and said metal selected from the group consisting of titaniumand zirconium and utilizing the resulting heat of the reduction reactionin heating the mixture containing said alloy to a sintering temperatureabove the melting point of the sodiumrchloride produced, so as to lowerthe time required to attain a sintering temperature for said alloy; (D)maintaining said sintering temperature for a suflicient period of timeto complete sintering of said metal alloy and to produce a massive metalalloy of said alloying metal and said metal selected from the groupconsisting of titanium and zirconium; and (E) isolating the metal alloyfrom the resulting reaction mixture. 1

6. The process of claim 5, wherein the alloying material is a metalwhich is introduced into said solid, finely divided mixture of chloridesof lower valence and sodium chloride just prior to subjecting saidsolid, finely divided mixture to reaction with the required additionalsodium in step (C).

7. The process of claim 5, wherein the alloying material is a chlorideof any alloying metal which is introduced into said solid, finelydivided mixture of chlorides of lower valence and sodium chloride justprior to subjecting said solid, finely divided mixture to reaction withthe required additional sodium in step (C).

References Cited in the file of this patent UNITED STATES PATENTS2,205,854 Kroll June 25, 1940 2,766,113 Chisholm et a1 Oct. 9, 19562,826,493 Garrett et a1. Mar. 11, 1958 2,827,371 Quin Mar. 18, 19582,828,199 Findlay Mar. 25, 1958 2,848,319 Keller et a1 Aug. 19, 1958FOREIGN PATENTS 386,621 Great Britain Feb. 16, 1933 686,845 GreatBritain Feb. 4, 1953

1. A PROCESS FOR THE PRODUCTION OF AN ALLOY OF A METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM WHICH COMPRISES THE FOLLOWING SEPARATE STEPS: (A) REDUCING A TETRAHALIDE OF A METAL FROM THE GROUP CONDIDTING OF TITANIUM AND ZIRCONIUM WITH AN AMOUNT OF SODIUM AT LEAST SUFFICIENT TO REDUCE SAID TETRAHALIDE TO A CORRESPONDING METAL HALIDE OF LOWER VALENCE, BUT INSUFFICIENT FOR STOICHIOMETRIC REDUCTION TO METAL, THEREBY CONTROLLING THE REACTION TEMPERATURE WITHIM A RANGE FROM THE MELTING POINT OF THE SODIUM UP TO THE MELTING POINT OF THE REACTION MIXTURE, SAID REACTION MIXTURE COMPRISING HALIDES OF LOWER VALENCE SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM SUBHALIDES AND THE CORRESPONDING SODIUM HALIDE, AND FORMING AN EASILY STIRRED, SOLID, FINELY DIVIDED REACTION MIXTURE WHICH IS STIRRED DURING THE REDUCTION REACTION, (B) INTRODUCTING AN ALLOYING MATERIAL SELECTED FROM THE GROUP CONSISTING OF A HALIDE OF AN ALLOYING METAL AND AN ALLOYING METAL INTO SAID PROCESS IN ANY STEP UP TO THE INTIATION OF THE SUBSEQUENT SINTERING PERIOD, (C) RECOVERING SAID SOLID, FINELY DIVIDED MIXTURE AND SUBJECTING IT TO REACTION WITH THE REQUIRED AMOUNT OF ADDITIONAL SODIUM FOR STOICHIOMETRIC REDUCTION OF ALL HALIDES PRESENT IN SAID MIXTURE TO FORM METAL ALLOY OF SAID ALLOYING REACTANT AND SAID METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM AND UTILIZING THE RESULTING HEAT OF THE REDUCTION REACTION IN HEATING THE MIXTURE CONTAINING SAID ALLOY TO A SINTERING TEMPERATURE ABOVE THE MELTING POINT OF THE SODIUM HALIDE BY-PRODUCT PRODUCED, SO AS TO LOWER THE TIME REQUIRED TO ATTAIN A SINTERING TEMPERATURE FOR SAID ALLOY, (D) MAINTAINING SAID SINTERING TEMPERATURE FOR A SUFFICIENT PERIOD OF TIME TO COMPLETE SINTERING OF SAID METAL ALLOY AND TO PRODUCE A MASSIVE METAL ALLOY OF SAID ALLOYING METAL AND SAID METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM, AND (E) ISOLATING THE METAL ALLOY FROM THE RESULTING REACTION MIXTURE. 